Cryptogrammic coding and decoding apparatus



Sept. 16, 1958 B. c. w. HAGELIN 2,851,794

CRYPTOGRAMMIC comma AND maconmc APPARATUS Filed May 23, 1956 4 Sheets-Sheet 1 INVE/VTOR: BORIS CAESAR WILHELM HAGELIN BY 40 2 7' {ATTORNEYS}.

Sept. 16,, 1958 B. c. w. HAGELIN CRYPTOGRAMMIC CODING AND DECODINGAPPARATUS Filed May 23. less 4 Sheets+Sheet 2 INVENTOR: BORIS CAESARWILHELM HAGELIN QM ATTO R N EYS p 1958 B. c. w. HAGELIN 2,851,794

CRYPTOGRAMMIC CODING AND DECODING APPARATUS Filed May 23, 1956 4Sheets-Sheet 3 IN VE N TOR BORIS CAESAR wlwfm GELIN av 9 I M ATTQ R NEYS Sept. 16 1958 4 B. c. w. HAGELIN 5 CRYPTOGRAMMIC CODING AND DECODINGAPPARATUS Filed May 23, 1956 4 Sheets-Sheet 4 INVENTOR: BORIS CAESARWILHELM HAGELIN BY f 22 ATTORNEYS CRYPTOGRAIVIMKC CODlNG AND DECODINGAPPARATUS Boris Caesar Wilhelm l-lagelin, Zug, Switzerland, assignor toAnstalt Europaische Handelsgesellschaft, Vaduz, Principality ofLiechtenstein Application May 23, 1956, Serial No. 586,768

Claims priority, application Switzerland May 26, 1955 7 Claims. (Cl.353) The present invention relates to a cryptogrammic coding anddecoding apparatus.

One general object of the invention is to provide a coding and decodingapparatus which is suitable for uses for which the existing coding anddecoding machines are too cumbersome and expensive. The apparatusaccording to the invention is particularly suitable for such uses indiplomatic service in which it has been preferred to up now to code anddecode messages without resorting to mechanical devices, on account ofthe comparatively small number and volume of the messages to betransmitted and of the difficulty of transporting the conventionalelaborate coding and decoding machines while keeping them under thepersonal control of the user when travelling.

A more specific object of the invention is to provide a coding anddecoding apparatus of small weight and small overall dimensions, whichmay for instance be carried by the user in his coat pocket.

A further object of the invention is to provide an apparatus of the saidkind in which the code key is continuously transmuted in way whichcannot be derived from the coded messages even by the most refinedmethods, whereby such apparatus affords a high or even absolute degreeof secrecy.

Still another object of the invention is to provide an apparatus havinga high degree of reliability in operation.

Further objects and advantages of the invention will appear from thedescription now to follow, in which reference will be had to theaccompanying drawings, of a specific embodiment of the invention, whichis given by way of example only.

In the drawings:

Fig. 1 is a View from above of the said preferred embodiment of theapparatus according to the invention, the cover of its housing beingremoved to show the internal parts,

Figs. 2, 3 and 4 are cross-sections through the apparatus, taken onlines IIII, IIIIII and IVIV of Fig. 1, respectively,

Fig. is a view from above of the lowermost, stationary disc of thetransmuting mechanism which the apparatus comprises,

Fig. 6 is a similar view of a rotatable disc of said transmutingmechanism,

Fig. 7 is an axial section through the stationary disc and a number ofrotatable discs of the transmuting mechanism,

Fig. 8 is a view from above of the apparatus with its cover partlybroken away and certain parts of the key disc mechanism removed to showone of the key discs from above,

Fig. 9 is a view from above of certain parts of the transmutingmechanism in their positions at the beginning of a transmutingoperation, and

Fig. shows some details of the apparatus comprising the key mechanismoperated by a key tape.

The coding and decoding apparatus shown in the Estates i em drawings isequipped with an alphabet wheel for direct reading. Instead of thelatter, a printing type wheel could be used without departing from thescope of the invention. Other possible departures from the embodimentshown in the drawings will be indicated after the description of thatembodiment.

The apparatus shown in the drawings generally comprises a rotatablecharacter disc, a transmitting mechanism for positioning that characterdisc, a key disc mechanism, a set of driving wheels for the latter, akey strip mechanism, separate sensing means for the key wheel and thetrey tape mechanisms, a common manual drive for the transmutingmechanism and for both said key mechanisms, and a counter mechanism.

The moving parts of the apparatus are supported on a number of shaftseach fixed in the bottom 1 of the housing of the apparatus. This housingpreferably is of rectangular shape with rounded corners and of such sizethat it can conveniently be lodged in the pocket of a coat. The saidbottom 1 has an integral flange 2 of small width extending upwards fromits periphery. The remainder 3 of the peripheral wall of the housing isintegral with the cover 4 and is connected by hinges 5 to one side ofthe bottom flange 2. The cover 4- has a circular recess 6 accommodatinga character ring 7 and a character disc 8 rotatable within saidcharacter ring. The character ring 7 which in the embodiment showncarries a set of alphabet characters is not rotatable but is readilyremovable for substitution of another ring bearing a different set ofcharacters. As shown in Fig. 8, the character ring 7 and the characterdisc 8 each bear a set of ordinary letters.

alphabetically arranged in opposite directions on the ring and on thedisc, but this is only one example of the sets of characters which maybe used. The alphabets may be of any desired nature and the sequence ofthe individual letters in each alphabet may be as desired. For instance,the letters on the ring '7 may be each on a removable plate so thattheir sequence can be varied at will.

The rotatable alphabet disc 8 is removably supported by the uppermostone 9 of a series of toothed discs which hereinafter will be referred toas transmuting discs. Connection between the alphabet disc 8 and theuppermost transmuting disc 9 is established by means of a few pins 10fixed to the transmuting disc 9 and engaging corresponding bores in thealphabet disc when the latter is mounted on the machine. The alphabetdisc is maintained in engagement with the pins 10 by means of an annularspring 11 lodged in a circumferential groove of the alphabet disc. Theuppermost transmuting disc 9 is secured to the upper end of a hollowshaft 12 which is rotatably supported on a stationary bush 13. The bush13 is welded at its lower end to a toothed disc 14 which is spaced fromthe bottom 1 of the housing by a number of tubular projections 16 onwhich it rests and to which it is secured by screws 15. The saidstationary bush 13 also supports an inner tubular shaft 17 which extendsthrough the whole length of the bush 13. At its upper end, above that ofthe bush 13, the tubular shaft 17 carries a radial arm 19 which servesas a unidirectional coupling member for rotating the transmuting disc 9.At its lower end, below that of the stationary bush 13, the tubularshaft 17 carries a gear wheel 18 for rotating the said shaft 17. Thecoupling arm 19 cooperates with an upwardly extending lug 20 of a disc20 which is rigidly connected to the transmuting disc 9 and whichtogether with the latter forms a housing for a spiral spring 21, theinner end of which is fastened to the stationary bush 13 and the outerend of which is fastened to one of the pins 10.

Between the uppermost transmuting disc 9 and the stationary disc 14, anumber of intermediate transmuting discs (five in the presentembodiment) 22, 23, 24, 25 and ,26 are rotatably supported above eachother on the hollow shaft 12. The hollow shaft 12 may be supported on aportion of reduced diameter of the stationary bush 13. The stationarydisc 14 is shaped as shown in Fig. 5, and the intermediate transmutingdiscs 22-26 are shaped as .shown in Fig. 6. All these discs are providedwith teeth on the major part of their periphery; however, the uppermosttransmuting disc 9 has no teeth. At a short distance from the last tooth(counted in the anti-clockwise sense as seen in Fig. 6) each of the saidintermediate transmuting discs .22 to 26 has a peripheral lug 27 whichis bent downwards at an angle, as shown in Figs. 6 and 7. A similar lug(not shown) is provided at the corresponding place of the uppermost,untoothed transmuting .disc9. The portion 28 of each intermediatetransmuting disc the periphery of which is not occupied by teeth or bythe lug 27 projects radially and serves as a support for a latch 33. Asimilar projecting portion 28 is also provided by the stationary disc 14as will be seen from Fig; 5. The projecting portion 28 has an aperture29 for reducing its weight and for another purpose which will appearlater on, and two bores 30 and 31 on opposite sides of the aperture 29.The bore 30 receives a pivot pin 32 on which the latch 33 is pivoted(see Fig. l), and the bore 31 is engaged by one end of a spring 34 theopposite end of which is hooked to a lateral arm of the latch 33. Theactive arm of the latch 33 extends clockwise from its pivot 32 and isadapted to be engaged by the bent-down lug 27 of the upwardly adjacenttransmuting disc. Fig. 1 shows such a lug 27 engaging the representedlatch 33. In order that the lug 27 may engage the latch when thetransmuting disc carrying the latch and the upwardly adjacenttransmuting disc are angularly displaced in relation to each other insuch a way that the lug 27 of the latter approaches the latch 33 on theformer, such latch has an inclined guiding face 35 against which the lug27 will abut, thereby rocking the latch 33 outwards in such a way thatthe nose of the latch will thereafter fall in behind the lug. The latchhas a rear arm, the end portion 36 is bent downwards and extends intothe aperture 29 of the corresponding transmuting disc and thereby limitsthe angular motion of the -latch under the effect of the spring 34.

Moreover, the intermediate transmuting discs 22 to 26 and the stationarydisc 14 each carry a ring 37 which is concentric with and rotatable onthe respective disc and which has an integral radial arm 38 projectingbeyond the toothed periphery of the disc. The end of that arm is bentdownwards for engagement with any desired tooth gap of the disc, asshown in Figs. 1 and 2. The projecting end of the arm 38 also is in thepath of the bentdown lug 27 of the upwardly adjacent transmuting disc.

Whenever the bent-down lug 27 of an upper transmuting disc is engaged bythe nose of the latch 33 carried by the adjacent lower transmuting disc,the two discs are angularly coupled with each other on one hand bythesaid engagement between the lug 27 of the upper disc and the latch 33 ofthe lower disc, and on the other hand by the lowermost part of the saidlug 27, which extends downwards in a direction parallel to the commonaxis of the transmuting discs, contacts the abutment 39 formed on thelower disc at the place where the latters own lug 27 has been bent downout of the plane of the disc, as shown in Fig. 7.

The transmuting mechanism thus far described is actuated by a toothedsegment 40 engaging the gear wheel 18 on the lower end of the rotatableinner tubular shaft 17 and formed on a manually operable actuating lever41 which is rotatably supported on the shaft 50 of the key discmechanism. The actuating lever 41 extends through a slot in the lateralwall of the housing as shown in Figs. 1 and 3 and outside the housinghas a handle 42 by which it can be operated by means of the thumb andindex finger of one hand, preferably the left hand.

The key disc mechanism shown in axial section in Fig.

3 comprises a certain number of key discs which are rotatably supportedon shaft 50, a bushing 51 being interposed between the shaft and thediscs. Each key disc is associated with a gear wheel for rotating thedisc. As shown in Fig. 3, there are six key discs numbered, from bottomto top, 52, 53, 54, 55, 56, 57. Their associated gear wheels aredesignated by 58, 59, 60, 61, 62, 63, respectively. Preferably, the gearWheels have different tooth pitches, and the key discs are provided attheir circumferences with radial slots of the same angular pitch as theteeth of their associated gear wheels. In each of these slots a lug 64in the shape of a small plate is supported on a tangential pin 65. InFig. 3, a few of these lugs 64 are shown. They are swingable on theirsupporting pins between an inner position in which they extend inwardlyand lie entirely within their respective radial slot in the key discwithout projecting beyond the periphery of the disc, and an outerposition in which they project beyond the said periphery of the disc. InFig. 3, three lugs 64 carried respectively by the discs 52, 53 and 56are shown in their outer position, and one ug 64 carried by disc 54 isshown in its inner position. The inner position will be designated asthe inactive position and the outer position as the active position ofeach lug 64. The width of each lug 64 corresponds to the axial distancebetween adjacent gear wheels, so that the lugs are retained by the gearWheels of the key discs in their active or inactive positions in whichthey have been set in assembling the mechanism. In the embodiment shownin the drawings, the diameters of the gear wheels decrease from thelowermost one upwards.

Each gear wheel of a key disc meshes with a toothed driving wheel fixedon a shaft 70 the axis of which is parallel to the axis of the key discmechanism. In Fig. 4, these driving wheels are designated, from thelowermost upwards, by 71, 72, 73, 74, 75 and 76. In addition to thesedriving wheels 71 to 76, the shaft 70 carries a ratchet wheel 77 byWhich the shaft 70 can be rotated from the actuating lever 41 by meansof a pawl 78 pivoted on the hub of lever 41 and engaging the ratchetwheel 77. Moreover, the shaft 70 carries a gear wheel 79 which by meansof an idler gear wheel 80 drives a further gear wheel 81 keyed to theinput shaft of a conventional counter mechanism 82. The motion of thepawl 78 is limited by a pin 83 on the hub. of the actuating lever 41.Feeler arms 92 which cooperate with the key discs 58 to 63 serve tocontrol the latches 33 of the transmuting mechanism, one such feeler armbeing provided for each key disc and one disengaging arm 93 associatedwith one of the feeler arms being provided for each latch 33. The feelerarms are swingably supported on a common shaft and each of them is actedupon by a spring 91 which tends to swing it towards the periphery of thecorresponding key disc. The disengaging arm 93 either may be integralwith the corresponding feeler arm, 92 as shown in Fig. 9, or it may berigidly fixed thereto.

As indicated above, the apparatus in addition to the key disc mechanismalso comprises a key mechanism controlled by a-perforated tape.designates a tape store comprising a roll of perforated tape 101. Thisroll is supported by a shaft 102 fixed in the bottom of the housing.From the roll 100 the key tape runs over a guiding roller 103 fromwhich. it leaves the apparatus through a slot in the adjacent side wallof the housing, as shown in Fig. 1. The guiding roller 103 is rigidlyconnected to a ratchet wheel (not shown) which can be moved step by stepby means of an actuating pawl 104 pivoted on the hub of the actuatinglever 41. That hub also carries a pin 105 which limits the angulardisplacement of the pawl 104. Both pawls 78 and 104 pivoted on the hubof lever 41 are pressed towards their respective motion-limiting pins83, 104 by springs A number of feeler arms 106 each integral with adisengaging arm 108 and acted upon by a spring 107 cooperate with theperforated tape 101. These feeler arms 106 and disengaging arms 108 areswingably supported on the same shaft 90 as the feeler arms 92 anddisengaging arms 93 of the key disc mechanism. Thus, each latch 33cooperates with two disengaging arms 93, 108, the first of which iscontrolled by one of the key discs and the other of which is controlledby the perforated key tape. Either of the two disengaging arms can beused at will by arresting the other of these arms. For this purpose,each feeler arm 106 of the tape mechanism is provided with a notch 109adapted to be engaged by a common locking member 95 pivoted at 94 andcooperating with all feeler arms. This locking member 95 also serves forarresting the feeler arms 92 of the disc mechanism, each of which feelerarms for this purpose is connected to a further arm 96 in which a notch97 for re ceiving the locking member 95 is provided. In the positionshown in Fig. l the locking member 95 arrests the feeler arms 106 of thetape mechanism and their corresponding disengaging arms 103, while thefeeler arms 92 and the disengaging arms 93 of the disc mechanism remainfree. By rotating the locking member 95 into engagement with the notches97 associated with the feeler arms 92 of the disc mechanism, the arms106 of the tape mechanism are freed While the arms 92 of the discmechanism are maintained out of operation.

Below the hub of the actuating lever 41, a cam segment 110 carrying acam 111 is rotatably supported on the shaft 50 of the key discmechanism. The cam segment 110 is provided with an arcuate slot 112concentric with the axis of shaft 50. This slot is engaged by a pin 113fixed in the hub portion of the actuating lever 41 and which is sopositioned thereon that it moves the cam segment along with theactuating lever 41 in both end portions of its motion, as will beexplained later on. The contour of the cam segment cooperates with onearm 114 of a bellcrank lever 114, 115 swingably supported on the shaft90 and the opposite arm 115 of which forms a common abutment for alldisengaging arms 93 and 108 both of the key disc and the key tapemechanisms.

In the following, the operation of the apparatus under the control ofthe key disc mechanism will be described, while its operation under thecontrol of the key tape mechanism will be dealt with subsequently,either of these key mechanisms being adapted to act on the trans mutingmechanism.

Normally, the actuating arm 41 is in its position shown in Fig. l, inwhich its handle 42 projects from one, preferably the left-hand, sidewall of the housing in such a way that it can easily be seized with thethumb and index finger of the left hand of the operator. In thisposition of the actuating arm 41, the transmuting mechanism is not inits initial position but already provides a transmuted reading. This istaken by means of the two alphabets on the stationary alphabet ring 7and the angularly displaced alphabet disc 8, for instance by selectingthe letter on the alphabet ring 7 which corresponds to the letter of thetext to be coded (or decoded), and by reading the letter on the alphabetdisc 8 which is just opposite the selected letter on ring 7. The letterthus read on disc 8 is the required corresponding letter in the coded(or decoded) text. This kind of reading will be used if the letters arearranged in the same sequence but in opposite directions on the ring 7and on the disc 8 as shown. However, if the letters are in arbitraryorder, the reading in decoding must be taken from the inner alphabet ifin coding it was taken from the outer alphabet, and inversely. If newthe actuating lever 11 is swung from its position shown in Fig. l in thedirection'of the arrow A, the toothed segment 417 will rotate the gearwheel 18 and the inner hollow shaft 17 anti-clockwise as seen in Fig. l.The coupling member 19 on shaft 17 then imparts its rotation to theuppermost transmitting disc 9 and to the alphabet disc 8, whereby thespiral spring 21 becomes tensioned. As the uppermost transmuting disc 9is thus rotated, its bent-down lug 27 sooner or later, depending on theprevious setting of the transmuting mechanism, engages the latch 33 ofthe do wnwardly adjacent transmuting disc 22. That lug 27 then slidesalong the inclined guiding face 35 of the latch until it contacts theabutment 39 of the lower disc 122 and the nose of the latch 33 falls inbehind it, whereby the upper disc 9 and the lower disc 22 becomeangularly coupled and the lower disc 22 partakes in the continuedrotation of the upper one 9. The disc 22 then in a similar way willcarry along its downwardly adjacent disc 23, the latter will carry alongthe disc 24, and so on, until all the discs 9 and 22 to 26 are in thesame angular position with their latches 33 just above each other andopposite their respective disengaging arm 93. When the lowermostintermediate trunsrnuting disc 26 is similarly arrested by the latch 33of the stationary disc 14, all the transmuting discs are arrested in thesame position, which is their actual reset or initial position for thenext transmuting operation. Meanwhile, the spiral spring 21 has beenfully tensioned. When the actuating lever 41 is released, it returns toits original position under the action of a resetting spring not shownin the drawing. Thereby, it releases the spiral spring 21 which then isenabled to rotate the disc 9 clockwise. As the actuating lever 41returns to its initial position, the coupling member 19 becomesdisengaged from the lug 211' of disc 9 and no longer controls therotation of the latter.

At the beginning of the working stroke of the actuating lever 41, thecam segment is in the position shown in Fig. 1, whereby its cam 111, byengaging the arm 114-, maintained the abutment arm in a position inwhich the latter prevents the disengaging arm 93 and 193 from engagingtheir respective latches 33. Towards the end of the said working strokeof the lever 41, the pin 1.13 meets the right-hand end of the arcuateslot 112 and from then on causes the cam segment 110 to rotate alongwith the actuating lever 41. The seg ment 110 thereby is rotated so farthat the cam 111 is disengaged from the arm 114 and the latter dropsonto the lower portion of the contour of the cam segment 110. Therefore,the abutment arm 115 releases all the dis engaging arms 93 and so thatthey are enabled to swing towards their respective latches 33 providedthat their associated feeler arms 92 and 106 are free as well. Insofaras the feeler arms 106 of the key tape mechanism are concerned, it hasalready been assumed that this mechanism first will be considered asinoperative; these arms 1116 therefore are arrested by the commonlocking member 95 engaging their notches 109, and these arms 106 neednot be considered for the moment. On the other hand, disengagement ofeach latch 33 by the corresponding disengaging arm 93 depends on whetherthe latters associated feeler arm 92 does or does not meet an active lug64 of the corresponding one of the key discs 52 to 57 when moving underthe action of its spring 91. Those feeler arms 92 which abut active lugsor prevent their associated disengaging arms 93 from moving towardstheir corresponding latches 33 to such an extent as to causedisengagement of these latches. On the other hand, those disengagingarms 93 the associated feeler arms 92 of which do not meet an active lug64 of their corresponding key disc will move farther towards thetransmuting discs and will engage and displace the latches 33 so as todisengage them from the lugs 27. Thus, when the actuating lever 41 hascompleted its working stroke, certain of the transmuting discs 9 and 22to 26 will be released by the latches of the downwardly adjacent discs,while the remaining transmuting discs remain arrested on theirdownwardly adjacent discs, the latches of which have not beendisengaged.

When the actuating lever 41 returns to its original position, theuppermost transmuting disc 9 is rotated in clockwise direction asalready mentioned. If the latch 33 on the downwardly adjacent disc 22has not been disengaged from the lug 27 of disc 9, the latter carriesthe disc 22 along with it in its clockwise rotation. However, if thelatch 33 on disc 22 has been disengaged from the lug 27 of disc 9, thelatter first rotates alone until its bent-down lug 27 meets theprojecting end of the adjustable radial arm 38 carried by the lower disc22 and only thereafter carries that disc along in its continuedrotation. In a similar way, the disc 22 carries the downwardly adjacentdisc 23 along in its rotation, either by means of its latch 33 throughthe full angle by which it is rotated, or by means of the radial arm 38of disc 23 through the angle of its rotation left after its engagementwith that arm. Similarly, all the remaining transmuting discs down tothe lowermost disc which has been released from engagement with thelatch 33 of its downwardly adjacent disc, will be rotated in a similarway; that downwardly adjacent disc may be the stationary disc 14 itselfor any other disc maintained stationary by the latch 33 of the disc 14or of another disc which is similarly maintained stationary. If none ofthe latches 33 has been disengaged, all the transmuting discs remain intheir said reset or initial position which they occupy at the end of theworking stroke of the actuating lever 41. Thus, the positions of thediscs of the transmuting mechanism are varied at each return stroke ofthe actuating lever, and this results in a new position of the rotatablealphabet disc 8, i. e. in a transmutation of the code. When thistransmutation is completed, that is, when the actuating lever hasreturned to its original position, the coded or decoded letter can beread. For each letter of the text, a reading of this kind is taken, andthe actuating lever is moved to and fro once before every reading.

-With each double stroke of the actuating lever 41, a rotation of thekey discs is efiiected due to the fact that the pawl 78 rotates theratchet wheel 77 by one step and thus rotates the shaft 70 and thedriving wheels 71 to 76 through a corresponding angle. These drivingwheels transmit their rotation individually to the several key discs 52to 57 by means of their associated gear wheels 58 to 63. Simultaneously,the counter mechanism 82 is advanced by one step by the gear wheels 79,80 and 81.

To change the setting of the lugs 64 of the key discs, these key discsmust be removed from their shaft 50 and bushing 51. For this purpose,the key discs can easily be withdrawn from the bushing 51 after removalof a cover disc 120 placed on the upper end of the shaft 50. At the sametime as the key discs are placed'on the shaft 50 and bushing 51, thecorresponding driving wheels are placed on their shaft 70 and thecorresponding bushing. In assembling the key disc mechanism, one firstplaces the driving wheel 71 on the bushing of the shaft 70, then oneplaces the gear wheel 58 and the key disc 52 on the bushing 51, making amark on the key disc, which indicates the initial position thereof, toregister with a fixed marking; moreover, care must be taken to bring thegear wheel 58 into mesh with the driving wheel 71. In a similar way, theremaining driving wheels and the remaining key discs with their gearwheels are mounted on their respective shafts and bushings. When all thedriving wheels and key discs are in place, the driving wheels aresecured against axial displacement by mounting a ring 121 on the shaft70,

while the key discs and their gear wheels are similarly secured by theabovementioned cover disc 120. Each key disc preferably carriesreference number, and for coded communication between two or morestations using similar apparatuses it is of course necessary that thecorresponding key discs of the several apparatuses are mounted in thesame initial position and bear the same reference number. In order toincrease the possibilities of variation it is recommended to supply witheach apparatus a plurality of sets of various driving wheels and variouskey discs with their corresponding gear wheels.

In the transmuting mechanism, various possibilities of mutual rotationof the transmuting discs '22 to 26' and.

14 can be obtained by varying the angular 'positions'of the adjustableradial arms 38 on the several discs. For instance, these radial arms 38could be set to obtain a relative rotation of the uppermost disc 9 byone division, corresponding to the angular distance between two adjacentletters on the alphabet disc 8, whenever the disc 9 is disengaged fromthe latch 33 on disc 22, to obtain rotation of the disc 22 in relationto disc 23 by two divisions, whenever the disc 22 is disengaged from thelatch on disc 23, and so on. f

In the described mode of operation, the disengagement of the latches 33is controlled by the key disc mechanism through the feeler arms 92 andthe disengaging arms 93; Meanwhile, the feeler arms 106 and theirassociated disengaging arms 108 are maintained inoperative by thelocking member 95 engaging the notches 109 of the feeler arms 106, asshown in Fig. 1. If it is desired to switch over to the key tapemechanism for disengaging the latches 33, one disengages the lockingmember 95 from the notches 109 and one brings it into engagement withthe notches 97 of the arms 96. Where the key tape as usual has five rowsof perforations, it is only necessary to provide five feeler arms 106.Then only five transmuting discs can be disengaged from each other andpartake in the transmuting operations. Care must then be taken thatthese five discs are suflicient for obtaining all the desiredtransmutations. Of course, for communication between two or morestations using the described apparatus with key tape operation, it isnecessary to use strictly identical key tapes and to give them strictlyidentical initial positions for each message to be transmitted. If eachkey tape or each portion of a key tape is used. only once, oneobtainsabsolute secrecy of communication provided that the perforation of thekey tape is unknown to the persons from whom the message is to beconcealed. The key tape is advanced by one step for each full cycle ofoperation, this being obtained by the action of pawl 104 on the ratchetWheel connected to roll 103. As soon as the end of a feeler arm 106penetrates into a perforation of the tape 101 at the moment it isreleased by the comm-on abutment arm 115, the corresponding disengagingarm 108 is swung towards the transmuting mechanism whereby it disengagesthe cor responding latch 33 from the bent-down lug 27 of the upwardlyadjacent transmuting disc. If on the other hand the end of the feelerarm 106 meets an unperforated spot of the tape, the disengaging arm 108remains in its inoperative position and the corresponding latch 33continues to arrest the said lug 27. Therefore, no relative angulardisplacement between the transmuting disc carrymg the latch and theupwardly adjacent one carrying the lug can occur in this instance.

Whether the disengagement of the latches be controlled by the key discmechanism or by the key tape mechanism, the cam 111 of the cam segmentalways maintains the arm 114 and thus also the disengaging arms 93 and108 in their locked positions during the major part of the workingstroke of the actuating lever 41; only at the end of that working strokeit permits the arm 114 to fall in onto the lower portion of the contourof the cam segment, whereby the abutment arm is allowed to release thedisengaging arms 93 and 108. During the return stroke of the actuatinglever 41 the arm 114 remains in its inner position until the cam segment110 is carried along with the pin 113 shortly before the end of thereturn stroke of lever 41, this time in anti-clockwise direction. Thecam segment then follows the lever 41 through such an angle that the cam111 again lifts the arm 114 and thus forces the abutment arm 115 back toits locking position, whereby it keeps, the disengaging arms; 93 and 108inoperative as shown in Fig. 1.

gears '94 Although a specific embodiment of the invention has beendescribed above, it is evident that the invention is not limited to thisembodiment. As already mentioned, the apparatus may comprise either thekey disc mechanism, or the key tape mechanism, or both of them. In steadof, or in combination with, the alphabet disc a type printing wheel canbe provided for printing the resulting text. The character wheel, thatis in the described embodiment, the alphabet disc 3, may carry two rowsof characters, for instance two concentric alphabetic series of letters.In such an embodiment, the disc before each transmuting operation maybepositioned with reference to an index so that the letter to be coded isjust opposite the said index. After the transmuting operation, theresulting letter is read from the other row of letters, either oppositeanother index or opposite the index first used. in this arrangement, themutual angular position of the two rows of characters may be adjustable.With this arrangement, a stationary character-carrying ring isredundant.

The stationary character-carrying ring such as 7 in the describedembodiment can be made easily removable, so that another rint carryingcharacters in a different sequence can be substituted for it. However,one could also provide the character-carrying ring with individuallyremovable tablets each carrying one letter or other character. Thiswould permit to change the sequence of the characters at random. Theposition of the rotatable character-carrying disc, such as the alphabetdisc 8 in the described embodiment, could be angularly adjustable withrespect to its supporting transmuting disc such as 9, so that theinitial position of the rotatable character-carrying disc with respectto the stationary character-carrying ring could be varied as desired.

1 claim:

1. A cryptogrammic coding and decoding apparatus comprising a shaft, aseries of transmuting discs coaxially supported on said shaft andincluding a stationary terminal disc at one end of the series, arotatable terminal disc at the opposite end of the series, andindividually rotatable intermediate discs between said terminal discs, aseries of self-engaging latches movably supported each on one of saidstationary terminal discs and intermediate discs and adapted to engagean adjacent one of said intermediate and rotatable terminal discs forangularly coupling said adjacent disc to the disc on which the latch ismounted, means for rotating said rotatable terminal disc in onedirection to produce successively its engagement by the latch mounted onthe intermediate disc to which it is adjacent and the engagement of eachintermediate disc by the latch mounted on the intermediate or stationaryterminal disc to which it is adjacent, means for rotating said rotatableterminal disc in the opposite direction, a key mechanism forindividually and selectively disengaging said latches each from its saidadjacent disc to permit relative rotation of the latter in the saidopposite direction, abutment means associated with each of saidstationary terminal and intermediate discs for limiting said relativerotation of its said adjacent disc in said opposite direction, and acharacter-carrying member an gularly coupled to said rotatable terminaldisc.

2. Apparatus as claimed in claim 1 in which said means for rotating therotatable terminal disc in said one direction comprise a manuallyoperable drive mechanism and a unidirectional coupling device betweensaid drive mechanism and said rotatable terminal disc, and in 1b whichsaid means for rotating the rotatable terminal disc in said oppositedirection comprise a spring device acting on said rotatable terminaldisc.

3. Apparatus as claimed in claim 2 in which said manual drive mechanismcomprises a toothed segment and gear Wheel meshing therewith, said gearwheel being mounted on said shaft and said shaft being connected to saidunidirectional coupling device.

4. A cryptogrammic coding and decoding apparatus as claimed in claim 1,in which said key mechanism comprises a shaft, a series of key discseach rotatably supported on said shaft, each of said key discs having atleast one controlling lug, and a series of swingable feeler arms eachcooperating with one of said key discs and adapted to abut saidcontrolling lug.

5. A cryptogrammic coding and decoding apparatus as claimed in claim 1,in which said key mechanism comprises a perforated tape having aplurality of rows of perforations, and a series of swingable feeler armseach adapted to abut said tape for control of the motion of said arm bythe presence or absence of a perforation at the point of abutment.

6. In a cryptogrammic coding and decoding apparatus, a transmutingmechanism for changing the position of at least one rotatablecharacter-carrying member comprising a shaft, a series of discscoaxially supported on said shaft and including a stationary terminaldisc at one end of the series, a rotatable terminal disc at the oppositeend of the series, and a plurality of individually rotatableintermediate discs between said terminal discs, cooperating abutmentmeans on each two adjacent disc-s for limiting their mutual angulardisplacement between two limit positions, a series of self-engaginglatches each movably mounted on one of said discs and adapted to engagean adjacent one of said discs as the latter and the disc on which saidlatch is mounted reach one of said two limit positions of their mutualangular displacement on relative rotation in one direction of that oneof them which is nearer to the said rotatable terminal disc of theseries, means for rotating said rotatable terminal disc in said onedirection, a key mechanism for selectively and individually disengagingsaid latches each from its said adjacent disc, and means for rotatingsaid rotatable terminal disc in the opposite direction, said rotatablecharacter-carrying member being coupled to said rotatable terminal disc.

7. In a cryptogrammic coding and decoding apparatus a transmutingmechanism as claimed in claim 6 in which said abutment means comprise anabutment member mounted in adjustable angular position on the one ofsaid two adjacent discs and adapted to cooperate with the other of saidtwo discs for limiting their mutual angular displacement on relativerotation in the said opposite direction of that one of them which isnearer to said rotatable terminal disc of the series.

References Cited in the file of this patent UNITED STATES PATENTS1,233,035 Damm July 10, 1917 1,416,973 Piersen May 23, 1922 2,050,919Brauer Aug. 11, 1936 2,093,731 La Boiteaux Sept. 21, 1937 2,389,093 TannNov. 13, 1945 2,706,079 Connolly Apr. 12, 1955 2,753,034 Hell July 3,1956

